This invention relates to coated abrasives and more particularly to coated abrasives in which the abrasive surface comprises a plurality of generally regular composite structures each of which comprises abrasive grain dispersed within a cured binder. The shape, spacing, size and composition of the composites can be manipulated to achieve a wide range of abrasive properties and for this reason the products are frequently referred to as “engineered abrasives” and this convention is adopted herein.
Engineered abrasives share a drawback, or more accurately an inconvenience, with all coated abrasives. Once they have been placed in position on a backup pad in the case of an abrasive disc, or on a machine in the case of a belt, it is difficult to identify the nature or source of the product being used without taking the abrasive off the device to which it is attached.
Various options have been identified to overcome this problem. These include most notably the use of different colors to indicate different grit sizes or types of surface treatment. This technique has been used commercially with some success but the approach depends on the operator knowing the “code” used by the manufacturer. With the advent of engineered abrasives a further technique becomes available for communicating information to the user in a convenient and very direct manner and this approach is at the heart of the present invention.